“A Pedro Costa musical — now, what would that be like?” I asked in these pages two years ago when the Portuguese filmmaker, appearing at REDCAT for the first-ever Los Angeles retrospective of his work, unveiled a 12-minute preview of his in-progress film about French actress and chanteuse Jeanne Balibar. Last May in Cannes, when Costa premiered the complete, feature-length version of Ne Change Rien, the answer was obvious: not like any musical you’ve ever seen before. Indeed, as with almost all of Costa’s work, the more you try to stick a label on his black-and-white study of Balibar in various stages of performance — “backstage documentary,” “concert film,” etc. — the more it evades capture, each new descriptor seeming at once inadequate and altogether too limiting. Is Ne Change Rien live, or is it Memorex? Only this much is certain: It is an experience.

The project, which grew out of a three-way friendship between Costa, Balibar and the late sound recordist Philippe Morel (to whom the film is dedicated), was shot piecemeal over a period of several years, as Balibar and musical collaborators (including guitarist/songwriter Rodolphe Burger) gigged around Europe and Asia and rehearsed material for her 2006 sophomore album, Slalom Dame. The result is an acutely perceptive film about the process of artistic creation, composed almost entirely of those moments that other films about performers omit or reduce to crassly compressed montages. In short, Costa, who previously documented husband-and-wife filmmakers Jean-Marie Straub and Danièle Huillet in the 2001 feature Where Does Your Hidden Smile Lie?, focuses on the work — the physical, emotional and psychological toil that goes into writing a lyric, perfecting a melody, interpreting a passage. Where most performance films — indeed, most performances — are about the seamlessness of the end product, Ne Change Rien endeavors to show us the seams. (At its first AFI Fest screening, Ne Change Rien will be preceded by Staub’s latest short, Le Streghe, Femmes entre elles.)

“The first time we showed the film, in Cannes, what I saw was that people started to walk out exactly when the work begins,” Costa told me earlier this month, sipping a beer and smoking a cigarette on the terrace of Lincoln Center’s newly renovated Alice Tully Hall, where Ne Change Rien was screening as part of the New York Film Festival. Tall and slender with mostly gray hair, dressed from head to toe in black, the 50-year-old Costa speaks in a low, ellipses-filled paragraphs that he seems to consider and reconsider even as he is speaking them. “In the beginning, there’s a bit of music,” he continued, “but when shit happens — I mean, when you have to concentrate, and Jeanne is not getting there, and the band is getting worried — that’s when I heard a couple of guys walking out and saying, ‘Oh, it started so nicely, but then. ...’”

For much of Ne Change Rien, Costa takes us inside Burger’s home recording studio, near the French-German border, as Balibar and company try out multiple variations on the Slalom Dame material (including, appropriately, one song titled “Cinéma”). It is, Costa said, where the idea for the film truly began to coalesce, “because those were more than rehearsals. They were inventing and trying things. Some songs you hear in the film are not on the record.” Then, in a a remarkable nine-minute shot, Costa shows Balibar taking detailed notes from an offscreen vocal coach while rehearsing for the title role in a 2008 production of Jacques Offenbach’s 19th-century opéra buffe, La Périchole. The teacher frequently interrupts Balibar’s performance, breaking it down line by line, measure by measure, to the singer’s — and some audience members’ — visible frustration.

“I thought she was very, very courageous in this singing,” Costa said. “I mean, this is an opera that Teresa Berganza sings; you can buy the EMI CD. But it takes a bit of courage just to sing. Singing is ... yeah, you could almost say that it’s the first thing, it’s even before language, and that connects back the Straubs, because they’re very suspect of language.” And like Where Does Your Hidden Smile Lie?, Ne Change Rien is also, by turns, a love story. “These looks they give to one another, Rodolphe and Jeanne ... everybody in Cannes thought they were lovers,” he said. “That’s okay. They are not. They’re good friends, but something happens ... it’s the work that creates a little bit this loving thing.”

Costa’s films have never been — and never will be — for everyone. Stationed somewhere between documentary and fiction, they demand an active, critical viewer willing to consider moving images in the same complex, constantly evolving terms that Costa does, whether he is observing a creative personality at work, or illustrating the realities (and fantasies) of dispossessed Cape Verdean immigrants in the crumbling Lisbon housing slum of Fontainhas. The focus of Costa’s three best-known features — Ossos, In Vanda’s Room and Colossal Youth — and two subsequent shorts, it is a terrain he has now mapped as indelibly as John Ford’s Monument Valley, complete with its own resident stock company. Commercial distribution has proven elusive for the filmmaker. Early next year, the Criterion Collection will release a DVD box set of Costa’s complete Fontainhas works, all of them available for the first time in the U.S.

Like the Straubs before him, Costa is consumed by the ethical and political implications of putting a camera before another human being. When he began filming in Fontainhas, he soon gave up the comforts of a traditional crew in favor of shooting by himself, less disruptively, on a small, digital video camera (a method he carried over to Ne Change Rien). Above all, he searches for the proper distance between filmmaker and subject. In the case of Balibar, that means an intimacy close enough to see every twitch of her neck muscles, yet entirely lacking in the intrusive vulgarity of so much music video.

Costa cited a source of inspiration in a musical number from Jean Renoir’s final feature, The Little Theatre of Jean Renoir, featuring actress Jeanne Moreau. “It’s just two shots — one where she’s standing on a stage and you see her whole body, and the second half of the song is a close-up. And you see a lot of things — it’s amazing what you see in two shots.”

He also has high praise for 1957’s celebrated “The Sound of Jazz” episode from the CBS television series Seven Lively Arts, featuring Billie Holiday (accompanied by Coleman Hawkins and Lester Young) performing a heartbreaking rendition of “Fine and Mellow.” “They have three cameras, perhaps, and they don’t abuse that. The distance in that show is amazing — especially with a person like Billie Holiday, you have to be careful.”

Indeed, in his films and in his conversation, there is a feeling that Costa aims to recover a purity of expression — a primacy of image, sound and meaning — inherent in the work of the earliest cinema pioneers. “When the Lumière brothers did a shot, the movement inside the shot is almost impossible to re-create today,” Costa said of the French siblings who were the first to publicly exhibit motion pictures. “I am always very afraid when I see a little dog crossing the street in a Lumière brothers film, afraid it’s going to be crushed by a Model T. It’s something very concrete, this menace. Then Chaplin did the same thing consciously, and Stroheim took it further. We could see so many things in those films that, today, you only see in some Filipino or Chinese films, or sometimes on TV, in some documentaries. Everything beautiful and everything dangerous and everything that has to do with society disappeared a little bit from films. I’m becoming very reactionary, but Straub would say you have to go back to the past to push things forward.”

To that end, Costa’s next project will take its partial subject the work of Jacob Riis, the journalist and social reformer who used early flash photography to create an enduring record of New York City tenements and slums at the end of the 19th century. But the film also promises to revisit the rubble of Fontainhas and its many walking wounded — the methadone addict Vanda (“star” of In Vanda’s Room), the dissolute construction worker Ventura (who occupies the central role in Colossal Youth). “It’s very fresh and I don’t know how it will be organzied, but it’s a good moment to go back and show what existed there,” Costa said as he took a last drag from his cigarette. “I think Riis is somebody who should meet Vanda and Ventura.”

Ne Change Rien screens on Thurs., Nov. 5 at 10 p.m. at the Mann Chinese 6. In addition, Pedro Costa will present Where Does Your Hidden Smile Lie?, Ossos and Colossal Youth Nov. 12-13 at the UC Irvine Film and Video Center. Complete schedule at www.humanities.uci.edu/fvc.